Process of making sulphuric acid and apparatus therefor



June 5, i923 F. G. STANTIAL Filed May 27, 1922 'Patented .lune 5, 1923.

maar? FRANK-c. STANT'IAL, or MELROSE, MASSACHUSETTS, Assrcfivoru To MERRIMAC CHEMICAL coMrAnv-y or WCBURN, MASSACHUSETTS, A CORPORATION or MASSACHUSETTS.

i PROCESS OF MAKING SULPHURIC ACID AND APPARATUS THEREFOR.

Application filed May 27, 1922. Serial No. 564,160.5

To all whom it may concern.:

Be it known that I, FRANK G. STANTIAL,

of Middlesex and State of Massachusetts,

have invented certain new anduseful Im` provements in Processes of IMaking Sulphuric Acid and Apparatus Therefor, of which the following is a specification.

This invention rela-tes to an improved `process of an apparatus for making Sulphuricdacid in which an acid product of relatively high concentration is produced.

In the operation of a chamber system for the manufacture of sulphuric acid it 'isl customary to circulate acid through theGay Lussac and Glover towers, the acid absorbing nitrogen oxide gases in the Gay Lussac tower and being denitrated and concentrated for reuse in the Gay Lussac tower by passing incontact with the hot burner gases in the Glover tower. It is also customary to feed chamber acid with the acid from the Gay Lussac tower to the Glover tower whereby it is denitrated and concentrated. As a resultdof this operation there is produced in the Glover tower niter free acid of about 58o to 60 B. in quantity more than is required to supply the Gay Lussac tower. l The excess of acid which corresponds in quantity with the chamber acid or make is withdrawn from the system but-.usually requires I'further concentration up to say 66 B. This concentrationmay be carried out in separate apparatus but Since the heat of theburner gases is more than su'tlicient,v

for theioperationof the Glover tower it is desirable and various attempts have'. been made to utilize this heat Jfor the Jfurther concentration of the part of the acid to be withdrawn 'from the system. A suggested method is to utilize the excess of heat by concentrating the acid in the Glover tower to the maximum extentand then diluting a portion of the concentrated acid for supplyving the Gay Lussac tower. This method however introduces an excess of water into the system besides being wasteful of heat.

According to my invention the Gay Lussac tower acid and chamber acid are mixed together and the mixture is divided.

between two Glover towersor preferably betweenv two shafts of the same AGlover tower, the acid in one shaft being denitrated duced by regulating the division of the acid 'and distributors from which a portion of and concentrated to the desired extent for '55 l use in the Gay Lussac tower while the acid( in the other shaft is denitrated andconcenv trated toV the maximum lextent for withdrawalfrom the system. y

The denitration and concentration of acid w00 in the Glover tower is accomplished by supplyinfr the two shafts with acid and burner gasesfoothin' parallel, the desired degree'of concentration in the'two shafts being pro- 5. and of the burner gases between the two shafts. Thus, the quantity ot acid necessary to supply the Gay Lussac tower is fed into one shaft of the Glover tower which is Supplied with Sulilcient burner gases to denitrate it and concentrate it to the proper 'l extent. The 1remainder of the mixture of acids and the remainder of the burner gases are supplied to the other Shaft of the Glover tower. 75 Apparatus suitable Yfor carrying out my fprocess is illustrated in `the accompanying drawings in which the figure is a vertical Section of the Glover tower.`

Referring to the drawing, 1 is the conduit which conveys burner gases'from the sulfuror ore burner and delivers them into the bottom of the Glover tower A. The tower 'd A is divided into two vertical shafts 2 and 3 by a wall 4. Each shaft contains a suit- 85 able fillingmaterial. Below the filling material' the tw shafts are in communication through the opening The top, of each shaft is'provided with an outllet pipe 7 controlled by dampers 6, leading to the `first of the lead chambers.v The apparatusfor mixing and distributing Gay Lussac tower acid and chamber acid to the two shafts of the y Glover tower and for withdrawing acid trated but are merely ,indicated by arrows and suitable legends. As indicated. chamber acid and acid from the Gay Lussac towerand water if necessary are fed into a mixer the mixture is delivered to each shaft. Acid for the Gay Lussac tower and the concentrated acid product' to be lwithdrawn `from the system are separately removedtrom the bottoms of the two Shafts as indicated. l

The system is supplied with niter -from the niter pots 8, 8 set in a depressionin the conduit l. The niter pots are connected in series by the pipe 9 and are supplied with nitrateand sulfuric acid and air or burner gases as indicated by the arrows and legends. The nitrioacid and nitrogen oxid containing gases pass through the pipe l0 and are delivered into the stream of gases leaving the Glover tower, thus by-passing the Glover tower. I

An example of the process as it may be carried out inthe above described apparatus is a follows:

It is assumed that the quantity of acid required to be fed to the Gay Lussac tower is about double the make7 of the set of chambers and that the chamber acid is about 530 B. and the acid from the Gay Lussac tower is about 58-60" B. and that it is desired to feed the Gay Lussac tower with acid of about 5380-60O B. The chamher acid and Gay Lussac tower acid are mixed together and about two-thirds of thev mixture is fed to shaft 3 while onen third of the mixture is fed to shaft .2. The How of burner gases is divided between the two shafts by means of the damp- .ers 6. In this particular instance it is found that about half of the burner gases are i required in shaft 3 and the other half may besupplied to shaft 2. Since the amount of acid owin in'shaft 2 is less than that lflowing in sha t 3, the concentration in shaft 2 will be considerably higher than in shaft 3 being in the neighborhood of from 630 to 66 B. The distribution of the gases between the two, shafts is regulated at all times to secure the desired concentration of l acid in shaft 3 for supplying the Gay Lusi as being of equal size but the invention is not limited in this respect. Shafts of diti'ei-, The invention ent size may be employed. is not limited to the particular construction of GloverA tower illustrated. Instead of a singleGlover tower divided into two shafts, two separate structures may be employed and the two4 shafts may be supplied with burner gases .through separate controlled as conduits or a branched gas conduit leading from the sulfur or -ore burner.

It is noted that the niter supply to the vchambers by-passes thev Glover tower andthe' burner gases are thus free from nitrogen oxids and the concentrated acid produced in the Glover tower is entirely free from oxids of nitrogen.

It is further noted that my process does not involve the introduction of hot and partially concentrated acid into the Glover tower or similar concentrating apparatus and the use of expensive apparatus and high repair costs, or loss of heat in case the hot concentrated acid is cooled, is avoided.

A further feature of my invention resides in that the gases leave the two shafts of the Glover tower at substantially the same temperature and equalization of the temperature of the gases leaving the two shafts before introducing it into the chambers is unnecessary. In order to secure this result I may resort to the use of different depths or sizes of packing in the two shafts.

I claim:

l. In the process of making sulphuric acid by the chamber process the steps comprising dividing the nitrous vitriol into sepa-i rate portions, contacting one of said portions with burner gases in quantity suicient to`denitrate and concentrate the same to thev desired degree, and contacting another of said portions of nitrous vitriol with burner gases in quantity sufficient to denitrate the same and concentrate the same to a degree different from the degree of concentration of said first-named portion.

2. In the process `of making sulphuric acid by the chamber process the steps comprising contacting separate portions of the nitrous vitriol'with separate portions of the burnergases, the ratio of the separate portions of nitrous vitriol to the separate portions of burner gases being unequal.

3. In the process of making sulphuric acid by the chamber process the steps comprising contactinga portion of nitrous vitriol sufficient when denitrated and concentrated to supply the Gay Lussac 'towers with a portion of the burner gases sufficient to de nitrate the same and concentrate the 'sainev `only to the degree required for use in the y Gay Lussac tower, and Contactin the remainder of the nitrous vitriol wit the remainder of the burner ases.A

4. In the process. of making sulphuric acid by-the chamber process the steps comprising dividing the flow of nitrous vitriol into parallel streams, dividing the iow of' burner gases into parallel streams, contacting one of said streams 0f nitrous vitriol withone of said streams of burner gases and delivering the resulting denitrated acid to the Gay Lussac towers, and contactin another of said streams of nitrous vitrio with another of said streams of burner gases and withdrawing the resulting denitrated acid from the process.

5. In theprocess of making sulphuric acid by the chamber process the steps comprising, mixing acid from they Gay Lussac tower with chamber acid, supplying a portion of the mixture suiiicient to supply the Gay Lussac tower to a denitrating and concentrating means and contacting the same with hot ing the: same with the remainder ofthe burner gases in quantity sullicieiit to deniytrate and concentrate said portion of acid only to the' desired degree for use Gay Lussactower, supplying the remainder fof the mixture of acids to another 'denitratf ing and concentrating means and contactburner gases,`

6. In.v the ,y rooess of makiiig sulphuric acid by the c amberA process the steps comprising circulating a stream of acid through a Glover tower and a Gay Lussac tower, adding chamber acid to said stream of acidv flowing fromI the yGray Lussac tower to the Glover tower, dividing the combined stream of acids into at least two portions, denitrating and concentrating one of said portions of the combined stream of acids by contacting thegsame directl with a portion of the hot burner gases an returning said portion -to theGay Lussac tower, and .denitrating same directly with anotherportion o the and concentrating a'nother portion offsaid combined stream of acids bycontactin `the hot burner gases and withdrawing said last named portion from the system.

7.. Apparatus for concentrating siilphuric acid comprising acid denitrating and concentrating towers, means for supplying said towers'with acid directly from the saine source, means for sup lying saidtowers with` hot vgases directy from the same source,and means for varying the ratio of -Y acid to yhot gases supplied to said towers.

f ers with hot gases directly from th'e sulfur or ore burners, and ,means for varying the ratio of said acids and said hot gases supplied to said towers.

9. In chamber apparatus for the manufacture of sulphuric acid, a Glover tower having two parallel shafts, means orsupplying each of said. shafts with a mixture of acids from the Gay Luac tower and from the chambers, means' for supplying eachof said shafts with hot burner gases, and l means for deliverin acid from onlyone of said. shafts to a ay Lussac tower and means for separately withdrawingacid'rom4 `the other of said shafts. 1

10. Apparatusfor making sulphuric acid -v comprising a Glover tower having a filling and apartition walldividing the Same linto two shafts, means for' supplying each of said shafts with acid, means for supplying each of said shafts with hot gases, means for delivering acid from only one of said shafts to a .Ga Lussac tower and means foi,"

separatel wit drawing acid from the other of said s afts.

11. Apparatus for making sulphuric acid com a' Gay Lussac tower, a pluralit of lover towers, means for suppl ing eac of said Glover towers with aci directly from the samesou-rce, vmeans for supplying eachy of saidjGlover ytowers directly with hot burner gases, means for delivering acid from 'at least one but not all of said Glover towers -to said Gay Lussac tower, and means for lseparatel withdrawing acid from another lover towers. v

of said ture.

FRANK e. STANTIAL.'

In testimony, whereof, I atlix mysignai 

